Proof Mass Effects on a Flextensional Piezoelectric Energy Harvester

This paper presents a comprehensive study of proof mass effects on a piezoelectric multilayer stack-based flextensional piezoelectric energy harvester (PM-Flex-PEH). For a weighted 23.7-gram PM-Flex-PEH, the proof mass of 10 grams, 20 grams, 50 grams, and 100 grams was applied on its top, respectfully, at different levels of vibrations. Both finite element modeling and experimental studies were carried out. An equivalent multilayer stack model and a full PM-Flex-PEH finite element model were developed. The impedance and sweep sin vibration tests were carried out on the PM-Flex-PEH. The simulation results were in alignment with the experimental results. The four mass ratios, including the mass ratio of the proof mass over the PM-Flex-PEH mass, and the mass ratio of the proof mass over the total mass and their square roots, were compared with the corresponding resonant frequency and generated voltage. It is shown that the generated voltage is linearly increase with the weight ratio of the proof mass over the PM-Flex-PEH by a factor of 2. However, the resonance frequency ratio for with proof mass over without proof mass is linearly decrease with the square root of the weight ratio of proof mass over the PM-Flex-PEH by factor of 0.32.